Answer:
Δm Δt> h ’/ 2c²
Explanation:
Heisenberg uncertainty principle, stable uncertainty of energy and time, with the expressions
   ΔE Δt> h ’/ 2
   h’= h / 2π
to relate this to the masses let's use Einstein's relationship
   E = m c²
let's replace
   Δ (mc²) Δt> h '/ 2
the speed of light is a constant that we can condense exact, so
   Δm Δt> h ’/ 2c²
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